Selma Bouvier (formerly Terwilliger-Hutz-McClure-Discothèque-Simpson-D'Amico) is one of Marge's older chain-smoking twin sisters. She works at the DMV and possesses a strong dislike for her brother-in-law, Homer, although on extremely rare occasions she shows kindness towards him and seems to tolerate him. She seems to despise Homer slightly less than her twin sister Patty Bouvier.
Selma Bouvier was born two minutes before Patty. Due to a childhood bottle rocket accident, she lost the sense of taste and smell . Selma is 42 years old and is five years older than Marge.
Selma's favorite film actor was reportedly Troy McClure, to whom she was briefly married, before discovering that it was just a publicity stunt by McClure. McClure took it one step further by wanting to have a child with Selma to help his career. Selma was willing to live a sham for a while, but broke it off when she realized she couldn't bring a child into a loveless marriage.According to Marge, Selma is "the one who likes Police Academy movies and Hummel figurines, and walking through the park on clear autumn days." Selma inherited her deceased Aunt Gladys's iguana, Jub-Jub, instead of her mother, Jacqueline, due to Jacqueline's dislike of Jub-Jub. Unlike Patty, Selma is very desperate to find love after seeing her Aunt Gladys' video will. She also asks Marge for advice to find love, saying that Patty is two minutes younger than she is.
Selma's favorite brand of cigarettes is identified as "Laramie Hi-Tars" while Patty's favorite brand of cigarettes is "Lady Laramie 100s"; they have been claimed by their mother to "have started smoking even before birth". It is shown that Patty and Selma started smoking as children when they gave their allowances to Marge (she would do their chores), and with all the free time they had, they took up smoking. The twins had melodic voices prior to starting smoking, and their trademark harsh voices after . The smoke and ash from the cigarettes turned her hair grey, originally blond. Since Patty is not a blond, but a redhead, this would make them fraternal twins. Patty and Selma share an apartment at the Spinster City Apartments complex and work at the Department of Motor Vehicles (DMV). They have on numerous occasions acted unprofessionally in the course of their jobs, such as smoking indoors, giving out licenses to unqualified drivers, or flirting with the customers (though Patty was eventually revealed to be a lesbian and didn’t tell Marge right away due to fear of Marge’s reaction. While Marge seems unsure at first, she eventually accepts Patty after saving her from a fraudulent marriage).
Selma and Patty have an avid (sometimes maniacal) love of the television show MacGyver. Selma nearly broke off her engagement with Sideshow Bob because he disliked the show, and both Patty and Selma stay up until 2:00 in the morning to watch the show. Patty and Selma also have an interest in traveling. They have visited Egypt, Lenin's Tomb in Russia, Easter Island, Mexico, and more mundane places, such as the Remington Horse Drawn Carriage Museum in Cardston, Alberta, Canada. Selma has also been to Duff Gardens. When they return home, they bring back numerous slides of them in these locations, and show them to the Simpson family, often describing the events in the most enjoyable way possible. The family, especially Bart and Lisa, are shown as barely staying awake during these shows.
Selma and Patty tend to be cynical and are noted for their addiction to tobacco smoking. In one episode during Season 26, they temporarily live with Homer. Homer places a ban on smoking, so instead they smoke electric cigarettes. Selma has presumably switched to chewing tobacco after adopting Ling. They have a strong, mutual (and reciprocated) dislike for their brother-in-law. Selma and Patty are shown to be older than Homer and Marge, but a birthdate has not been given. It is presumed they are in their mid to late 40s, since Selma has gone through menopause and the twins are shown as teenagers when Marge is around Lisa’s age. She weighs 168 pounds exact  and is considered overweight like Patty, though they are not as fat as Homer. As teenagers and children, they are average weight, while Homer was still fat.
Unlike Homer, who usually makes a perfunctory (if not particularly sincere or committed) effort to be polite to his sisters-in-law out of respect for his wife, Patty and Selma do not have hesitation in treating Homer with open rudeness and contempt. There were several instances where they did not seem to care when Homer faced a life-threatening situation. For instance, when Marge rushes to the hospital after receiving a telephone call that Homer had suffered a heart attack at work, Patty and Selma — instead of going to the hospital and comforting Marge in her time of need — remained seated at the kitchen table, continuing their activity of cutting coupons, gasping in amazement at a five cent discount and behaving as though nothing was wrong. They later attempted to set up Marge with a (rather sleazy) man as a replacement for Homer, regardless of the fact that Homer was still very much alive.
When Homer faked his demise to get out of work, Patty and Selma showed up at the Simpsons house holding a tombstone inscribed with "Homer J. Simpson. We are richer for having lost him." This gift as well as the fact that they been saving this since Marge's wedding causes her to throw them out . When Homer was revealed to be alive, the twins use the tombstone as a coffee table. It should also be noted that in the beginning of the series, Patty and Selma's catchphrase was, "Marge, why did you ever marry him"? And then listed one single reason why he is a terrifying husband.
Despite this, Selma occasionally (though very rarely) shows fonder feelings for him; a prime example is in "Selma's Choice", when Selma takes Bart and Lisa to Duff Gardens and is worn out due to the children running off and Lisa becoming drugged, later expressing admiration for Homer's ability to cope with the children. On another occasion Homer left Marge to try to find a better job to give her what she deserved, and Patty and Selma rejoiced, but when she saw how unhappy Marge was Selma gave in and told her where Homer was working. Selma also pretended to be married to Homer so she could adopt Ling, since the adoption agency frowns upon single parents. When it is revealed that the head of the agency was herself raised by a single parent, she allows Selma to keep Ling.
Homer, for his part, despises the twins just as much as they dislike him, but he has shown occasional bouts of kindness towards them, and Selma in particular (much to the twin's surprise). He does this more because of his love for Marge than for any love for his in-laws. One example is, when Sideshow Bob was running for mayor, Homer voted for him just because there was a Selma-killing policy. Another example is, Homer once made fun of the fact that Patty was a lesbian.
Selma's bad traits have not gone unnoticed by the populace of Springfield and even their family; her mother even stated that "[they're] a sort of evil", having raised them her entire lifetime.
Patty and Selma also rarely shave their legs for some reason, although this isn’t always shown, given that both twins wear dresses that expose their (hairless) legs. Also, they have been shown in swimsuits without leg hair.
Despite being twins, Patty and Selma have very different track records when it comes to finding dates. According to Marge, Patty chose a life of celibacy (possibly because she’s a lesbian), while Selma had celibacy thrust upon her. Her standards are extremely low, as evidenced by her comments on Mr. Burns: "Single, eh? Well, he passes the Selma Test,” despite him being old enough to be her great-grandfather.Selma has actively sought out a husband, having been married a total of five times. Her current name has evolved into Selma Bouvier-Terwilliger-Hutz-McClure-Discothèque-Simpson-D'Amico, after failed marriages to Sideshow Bob, Lionel Hutz, Troy McClure, Disco Stu and Abraham Simpson. She thought she married (Fit) Fat Tony, because she didn't understand Italian -- and didn't realize the ceremony was for her to become his "goomar" (mistress), rather than his wife. One person Selma refused to marry was Apu Nahasapeemapetilon, because she said her collection of last names was long enough without Nahasapeemapetilon added to it. Selma claimed that she would only marry for love, or possibly money in the future. There is photographic evidence that she slept with Apu after Homer and Marge's second wedding (presumably in Bart's bedroom, due to various belongings belonging to Bart Simpson and Bart impatiently and irritably looking at his watch while watching them sleep). Selma later began dating and later married Grandpa Simpson, who had previously dated her mother. Eventually, however, the couple realized that they just cannot make it work because of his age and her career and called it quits.
Selma has also dated Hans Moleman, Moe Szyslak, and pitifully, Barney Gumble. She also, alongside Patty before the latter came out of the closet, did some sexually questionable actions (possibly rape) such as tricking a TV repairman into acting as a "gentleman caller" by unplugging their TV set and then claiming it was broken, as well as going into a line for sex offender registration once with Patty, although whether this was due to mistaking the line for another line or if they did sexual actions to deserve sex offender registration is never specified.They have also flashed their cleavage a few times.
Unable to find companionship in a husband, Selma has also sought to have children. At one point she was considering using a sperm donor. After babysitting Bart and Lisa for a day, she realized that although she wanted someone to love, she was not ready to have children and wound up adopting Jub-Jub, her Aunt Gladys' pet iguana. Later however, a very menopausal Selma adopted a Chinese baby, Ling Bouvier. During the adoption process, Selma pretended to be married to Homer, since the Chinese government only allows children to be adopted by married couples. When the fraud was exposed, Selma managed to keep the baby, as a Chinese dignitary who had also been raised by a single parent became sympathetic.
As children, Selma and her sister Patty were apparently domineering towards Marge and ridiculed her ambition of becoming an astronaut. Their relationship seems to have improved over the years. As adults, the Bouvier twins have a friendly relationship with their sister and frequently visit the Simpsons. They seem relatively fond of Maggie, Lisa and Bart, but seem to like them more when they are young: "The older they get, the cuter they aren't." They have, on occasion, watched the kids when their parents were out of town. However, Bart and Lisa would rather not be around when their aunts visit. They once spend a nightmarish weekend with their aunts, making Bart and Lisa appreciate Marge when she returns . Their idea of bonding with Lisa includes tutoring her in the belief that men are pigs, using Homer as the prime example. Also, Selma was responsible for Lisa getting drugged at Duff Gardens, although Selma is remorseful once she witnesses Lisa’s crazed behavior.
Their relationship with Homer remains one of mutual dislike (although Selma gradually grows to become more tolerant towards Homer and often experiences brief moments of kindness from both Homer and Selma, but these examples are far and few between) which involves a continuous exchange of insults from day one. They unfavorably compare their brother-in-law to a caveman, suggesting him capable of trading Maggie for beer and a nudie magazine.
Selma and Patty have occasionally expressed their common hope that Marge will eventually divorce Homer. They have unsuccessfully offered to help Marge find a replacement for Homer. The twins went so far as to have a billboard built trying to convince voters to have Homer kicked out of Springfield .
Their hostility towards Homer has even led to pushing him off a bridge, although they half-heartedly claim they did this in order to get Homer to his surprise party, which was conveniently on a boat passing beneath the bridge at the time .
Selma once took the Simpson kids on a disastrous trip to the Duff Gardens theme park. Unable to control the children, Bart manhandles several animatronic characters and sneaks on a ride that he is not old enough for, and Lisa goes on a psychedelic trip after drinking "water" from an It's a Small World - like boat ride (later swimming naked in the Fermentarium and exclaiming "I am the lizard queen!"). After that, however, Selma returned home with the children and asked Homer how he does it, referring to raising children. She mentioned children and they exchanged a hug, implying that Selma is slightly more capable of overcoming her dislike of Homer than Patty .
In "Holidays of Future Passed", at age 72 she has a lovebot who runs away with Patty's love bot, much to their annoyance.
Four Great Women And A Manicure
In this episode she portrays an English Queen Elizabeth I, who is in search of a man, and eventually settles for Sir Walter Raleigh, who likes one of her ladies in waiting, played by Marge. Meanwhile, a rejected King Julio of Spain, wants his revenge, and sends his armada to England and the Elizabethan Armada catches on fire thanks to Sir Walter Raleigh and his smoking pipe, soon the English Armada abandon the ship and the flaming boat defeats the Spanish Armada, Raleigh is granted an honor and has permission to marry the Lady In Waiting. She proclaims: "I don't need a man, whereas I have England", to which Moe replies "You keep telling yourself that".
Patty and Selma appear in the level NeverQuest in the form of a two-headed dragon who attack the Hobbit-like forms of Rod Flanders, Todd Flanders, and Ralph Wiggum. They also appear earlier on in Mob Rules as people Marge can use to protest the sales of the Grand Theft Scratchy video game to minors.
Patty and Selma are seen running the street races in all the levels except level 7, when zombies take over Springfield. They will unlock a bonus car if the player can complete all three street races in each level. In levels 2 and 5, they can both be seen working at the DMV. The player can talk to them whilst inside the DMV.
Behind the Laughter
Matt Groening has mentioned that he named the Simpsons after his own parents and two younger sisters; he has an older sister named Patty who is an art dealer. Julie Kavner has proclaimed that she had difficulty coming up with the voices for the Bouvier sisters, until producer James L. Brooks suggested that she voice Patty and Selma as characters "that suck the joy out of everything."
- As shown in the intro to To Surveil With Love, Selma is a hula dancer.
- In The Blue and the Gray, it is revealed that Selma's hair is actually blonde, the gray being smoke from her constant usage of cigarettes, but flashbacks show Selma's hair being gray as a child. However, it is possible that it was colored gray in said flashbacks because she was smoking at a young age. It isn't surprising, seeing as she smokes in flashbacks as well. It was grey as a baby also, but this is likely because her father smoked.
- Due to her brief marriage to Abe Simpson, Selma is not only Homer's sister-in-law, but formerly his stepmother, although she is young enough to be his sister.
- In The Simpsons Game, Selma was one of the dragon heads in NeverQuest and the other was Patty.